Wire butt welding equipment is generally known in the industry as a means for joining the ends of two or more wires, sometimes creating a closed wire figure. Wire welders use clamps to grasp the respective ends of wires to be welded together. The clamps hold the respective ends of the wires in contact with each other, and the welder applies a tip force to press the ends of the wires together. In a resistive wire welder, electrodes within the clamps contact the wire and pass current through the respective wires to be welded. The resistance at the juncture of the two wires causes a buildup of heat, which welds the wires together.
The wire butt welders known in the art are designed to weld straight pieces of wire. Wire welders associated with flexible wire bending machinery, however, must be capable of accommodating a variety of parts. Curved wires, wires with angled segments, or wires needing to be welded at an angle relative to each other (as opposed to forming a straight line with the two wire ends) require angular adjustment of the electrodes of the wire welder to properly align the ends of the wires. Known wire welders are designed with clamps that are not, themselves, capable of angular adjustment. Instead, the known wire welders rely upon electrodes that must be angularly adjusted. To accommodate this adjustment, the wire welders known in the art use electrodes with slotted mounting holes. An exemplary prior art electrode is illustrated in FIG. 13. The electrode 330 has grooves 331 and 332 positioned at either side of the electrode. The grooves 331 and 332 are substantially cylindrical such that they receive and maintain contact with the outer surface of a round wire. In a wire butt-welder, two electrodes 330 grasp each end of the respective wires that are to be welded by the welder. The electrodes 330 are positioned substantially opposite each other, across the centerline of the wire. A holding force clamps the wire between the electrodes 330. The electrode has a through-hole 334 used to locate or attach the electrode to a jaw of a wire butt-welder. In addition, the electrode has arc shaped slots 333 that facilitate angular adjustment of the electrodes relative to the clamps. By adjusting the angle of the electrodes 330, the ends of the wires to be welded can be aligned with one another.
Over time and repeated use, slotted electrodes slip relative to the clamps. Further, all types of electrodes accumulate build up due to welding material that has not been cleaned. This build-up affects the angular alignment of wires held by the electrodes 330. In addition, the electrodes 330 typically need to be adjusted every time the wire butt-welder is configured to run a different part. The electrodes are frequently adjusted to maintain proper alignment of the wire ends within the welder, particularly in situations where a welder runs high volumes of parts or parts requiring a variety of angular alignments. The slotted electrodes previously known in the art required individual adjustment—meaning each electrode needed to be adjusted by loosening bolts screwed through the slotted holes and manually changing the angle of the electrode. This process was difficult and time-consuming in part because the electrodes tend to slip when the bolts are re-tightened. The time required to adjust the electrodes reduces the productivity of the welding equipment. The adjustment and slippage also imparts mechanical wear on the electrodes, both at the wire/material interface surface with the electrodes and at the mounting surface of the electrode. Reducing the need for adjustment, or simplifying the process of adjusting electrodes, is therefore desirable.
Slotted, angularly adjustable electrodes are more expensive than similar electrodes that have a simple through-hole for fixed mounting to the clamp. Electrodes used in wire butt welders are a consumable part of the machine, due to the stresses imparted by high temperatures, electrical current, and mechanical wear. Reducing the cost of the electrodes used on the wire welder is therefore desirable.